Hi friend!
Since the maximum supported length of optical fibers and optical cables is 10 meters, when the distance between the two switches is greater than 10 meters, use network cables for stacking. However, it is not recommended that you perform such long-distance stacking, because it is prone to problems, which will cause stacking failure, failure to start the service, or packet loss. You can use the stacking tool to stack.
Gald to help!